Question

A motorcycle is moving at a speed of 21 m/s. The driver applies the brakes, giving hum an acceleration of -2.4 m/s^2. After 2 seconds of braking, what is the speed of the motorcycle?

A. 25.8 m/s
B. 16.2 m/s
C. 4.8 m/s
D. 2.4 m/s

Answer 1

Answer;

B. 16.2 m/s

Explanation;

Using the equation;

v = u + at; where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken;

u = 21 m/s, a= -2.4 m/s^2 and t = 2 seconds

Therefore;

v = 21 + ((-2.4) × 2)

  = 21 - 4.8

  = 16.2 m/s